Art of hardening and toughening metals.



UNITED STATES OFFIOE.

AM C RGHWARD; or nsw romi. N. Y.- ART 0? HABDENING AND TOUGHENJNG METALS.

Specification of Letters Patent. Application filedDecember 7, 1905. Serial No. 290.829.

' Patented Oct. 9, 19'oe.

county, and State of New York, have invented certain new and useful Improvements in the Art of Hardening and Toughening Metals, of which the following is a specification.

Thisinvention re ates to a process for making castings of iron and steel hard and tough, and while applicable to castings for any use or purpose the process is especiallyapplicable to the production of armor-plates and the like. I

r In explaining the carrying out of the invention it will suffice to describe the actual plate'-such, for example, as an armor-plate suitable for a war-shlp, although the pro cedure may be sli htly varied, as well as the proportions of t e ingredients employed when dealing with castings for this and for .otheruses. l,

For making an exceptionally hard ,and

tough armor-plate the following ingredients and proportions may be employed: carbon steel, ure, with 0.20 carbon,) 81.5 nickel, 10.;0;,.c romium, 5.0; manganese, 2.0; tungsten, 1.0; vanadium, 0.5; total, 100.0.

The carbon steel used should be practically pure with about 0.20 of carbon. The nickel and chromium used should be the ure metal. The tungsten, manganese, and vanadium used may be in the forms of ferrotungsten, ferro-manganese, and ferrowvana dium; but the best results will be attained with the pure metals. .A larger percentage of manganese than that given above may be used without disadvantage; but such a large percentage will not ordinarily be required.

The steel and alloying metals may be melted together upto 2 ,500 Fahrenheit; but care must be taken not to exceed 2,600 Fahrenheit if possible; or the nickel, chromium, and manganese may be melted together separately from the steel and broughtto a temperature of 2,500'Fahrenheit and the tun sten and vanadium then added. This mo ten mixture of the alloying metals will be added to the molten steel. A small percenof this metal given above.

Great care should be taken to prevent the temperature of the molten steel alloy from ciently to be handled, it is taken out.

treating the above, the bat may e com osed of carbolic acid, thirty parts, linseed-oi seventy arts;

' rising eheve 2,600 Fahrenheit, and when a is molten and read poured into the mol The mold should be of metal strong enough to hold the metal casting in place, and it should be lined where it comes in contact it should be at once .with the casting with a plaster composed of the black oxid of manganese mixed with any suitable medium, as water, molasses, &c., and allowed to dry. 7 this lining of the mold with manganese dioxid is in order to surround the casting with a substance that will not add silicon or carbon to the casting. The absorption of carbon or silicon from the mold would in many cases injuriously modify the alloy of the casting if brought into contact with the same.

When the casting shall have oeen in the mold long enough for. it to set or harden si i flllie sooner it is taken out the better, and the more rapidly it can be cooled to the point where it can be safely removedthe better. After being removed from the mold it is taken at once to the press to be pressed. Its temperature'at this time should be about 2,100 Fahrenheit ora little less or otherwise it may have to be reheated. It is preferable to press the casting 'without reheat ng, as the grain will then be finer and harder. In the press it should be reduced to about one-third Pressing plates in It may be explained that a bath composed of a phenol and some fatty substance. Preferably, for the purpose of late roduced as described total, one hundred. This bath shoud be kept as coolas possible, and this may be effected with a jacket of runnin water or one of ice. The object is to 000% the late quickly, and it should remain in the bat until perfectly cool. The plate should have a temperature as near 1 ,800 Fahrenheit as possible when submerged, and it should not be removed until cold.

tage of the chromium will be lost in the melting; but this is provided for in the proportion" portion in volume of t e liquid to the metal Fahrenheit and may,

shall be about seven to one. A portion the oil goes off in vaplor and a trace only of the carbon goes into t e plate. One submersion of the plate is sufficient, rovided it is hot enough when it enters the ath, and this temperature should not be lower than 1,200", be as high as 2,000 Fahrenheit.

The proportion of the ingredients of the.

For carbolic acid (phenyl hydroxld) any phenol or suitable phenol derivative may be employed with good results, as creosote, (a

monohydric phenol) for example. The Word phenol as herein used is intended to include any one or all of these substances. The heno'l if used pure causes such a sudden shock that the shrinkage and tightening of the outer skin of the metal causes the steel to crack. Therefore an oil or some fatty sub- .stance is mixed with the phenol to modify the effect. The oil or fat prevents the metal from cooling suddenly, so that the ores of the metal remain open for a very s ort period of time. During this period the phenol penetrates and acts on the inner metal, thereycarrying the depths of hardening to any degree required; em eratures govern the action a great deal. A igh tem erature or a series of high temperatureswil hardening to the center of the metal; a low temperature will only carry in a short distance.

By the word manganese as herein used is meant the metal manganese or any of its .compounds or'mixtures which will yield manganese by reduction in the process described. This invention is not llmited to carbon I carry the.

steel as a basic metal or stock for the alloy. If crucibles are used, pure iron may be used as stock; but pure car alloy.

Obviously the pressing of the casting may be omitted. in some cases; but this is an important step in the preparation'of hardened plates.

Having thus described my invention, I claim' v 1. The herein-described improvement in the art of hardening and toughening iron and steel, which consists in forming an alloy of the metal with small quantities of nickel,

chromium, manganese, tungsten and vanadium, then casting the same in a mold, and then immersing thehot casting in a bath containin'ga phenol and allowing it to cool therein.

2. The herein-described improvement in the art of hardening and toughening steel, which consists in melting together steel, nickel, chromium, manganese, tungsten and vanadium, casting the molten metal a mold in contact with a surface containing manganese, then ressing the casting, and finally immersing it until cold in a cold bath consisting of a fatty substance and a phenol.

. 3. The herein-described improvement in the art of hardening and toughenin steel and iron, which consists in fusing an a'l' 0y of carbon steel, nickel, chromium, manganese,

tungsten and vanadium, then casting the alloy in contact with a surface containing manganese, and then, while still at a suitable temperature, submitting the casting to pressure, and finally immersing the pressed casting, while at a suitable temperature, in a cold bath consisting of carbolic acid and a fatty substance and. allowing it to remain so immersed until cold.

In witness whereof I have hereunto signed my name, this 5th day of December, 1905, in

the presence of two subscribing witnesses.

JAMES CHURCHWARD. Witnesses:

HENRY CoNNET'r, H. G. How.

on steel is best, and it provides the chea. est way of ettin an evendistribution of t e carbon t oug out the 

